Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Date of Award

Spring 2011

Document Type


Degree Name

Doctor of Audiology (AuD)


Department of Communication Sciences and Disorders


Ayasakanta Rout

Brenda M. Ryals

Dan C. Halling


The primary objective of this study was to determine if acceptable noise levels (ANLs) in elderly, hearing-impaired listeners were dependent on speech intelligibility and listener attention levels. Acceptable noise levels (ANLs), expressed in decibels, is defined as the maximum background noise level that is acceptable while listening to and following a story. Connected speech test (CST) sentences were recorded with clear speech, conversational speech and temporally altered, fast-rate speech. Thirty-five, elderly, hearing-impaired individuals (61-97 years, M=75) with symmetrical, bilateral sensorineural hearing loss participated. Most comfortable listening levels (MCL) and background noise level (BNL) measurements were completed for each speech stimulus under conditions of attention and non-attention. ANLs were calculated and results were compared to a previous, similar study with younger, normal-hearing individuals. A significant main effect of stimulus type was found suggesting that ANL is dependent on the intelligibility of the target speech signal. Although a significant main effect of attention was not reached, a significant interaction between attention and stimulus type was found showing the condition of attention to produce lower mean ANLs for clear speech and higher ANLs for fast-rate speech. In comparison to the younger, normal-hearing group, the participants in this study had higher ANLs, overall. These findings are contradictory to previous findings. Knowledge of these results may guide clinical audiologists in counseling patients and family members on communication strategies.



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